Non-deterministic output with ZSTD_createCDict_byReference

[cdcxd]

Describe the bug

It's not a logical bug. Just the ZSTD_createCDict_byReference would output differently if the input data is directly adjacent to the dict. Making the output non-deterministic if the input is randomly allocated.

I found there's a opt-in param ZSTD_c_deterministicRefPrefix , that solves the problem for refPrefix. They share exactly same mechanism. But it doesn't apply to the CDict.

And the comment https://github.com/facebook/zstd/blob/dev/lib/zstd.h#L2275 said

 * If you really care about determinism when using a dictionary or prefix,
 * like when doing delta compression, you should select this option. 

So I believe it might also need to apply to the new API ZSTD_createCDict_byReference

To Reproduce

Compressing one 256 KB random buffer with a random 64 KB ZSTD_createCDict_byReference() dictionary,
contiguous vs separated:

level 2 | byReference     | MISMATCH
level 3 | byReference     | MISMATCH
level 4 | byReference     | MISMATCH
level 6 | byReference     | MISMATCH 
level 2 | byReference, deterministicRefPrefix=1               | MISMATCH
level 2 | byCopy (control), default                           | IDENTICAL

Expected behavior
Opt-in deterministic mode

Screenshots and charts
If applicable, add screenshots and charts to help explain your problem.

Desktop (please complete the following information):

• OS: [Ubuntu]
• Version [24.04]
• Compiler [gcc13.3.0]
• Flags [any flag]
• Other relevant hardware specs [AVX2 , 16 cores]
• Build system [Any]

Additional context

I'll create a PR with unit test.